Process for breaking petroleum emulsions



' itent diiap. 55, 1938 UNITE STATES PROCESS FOR PATENT OFFICE,

BREAKING PETROLEUM EMULSION S Melvin De Groote, St. Louis, Mo., assignorto The 'l'rct-O-Lite Company, Webster Groves, M a

corporation of Missouri" No Drawing. Application June 21, 1937,

. Serial No. 149,472

Claims.- (0!. 196-4) curring waters or brines, dispersed in a moreorless permanent state throughout the oil which constitutes thecontinuous phase of the emulsion. 10 They are obtained from producingwells and from the bottom of oil storage tanks, and are commonlyreferred to as fcut oil", "roily oil, emulslfled;oil and bottomsettlings.

The object of my invention is to provide a novel and inexpensive processfor separating emulsions of the character referred to into theircomponent parts of oil and water or brine. Briefly described, my processconsists in subjecting a petroleum emulsion of the water-in- 011 type tothe action of a treating agent or demulsifying agent of the kindhereinafter described, thereby causing the emulsion to break down andseparate into its component parts of oil and water or brine, when theemulsion is permitted to remain in a quiescent state after treatment, oris subjected to other equivalent separatory procedures. v

The treating agent or demulsifying agent contemplated by my processconsists of a sulfopolyhydric alcohol ester of a detergent-formingcarboxy acid, of the kind hereinafter described in detail.

It has long been known that various organic acids of fairly highmolecular weight, combine with alkalis to produce soap or detergent-likematerials. Such acids include the higher fatty acids derived from animalor vegetable sources, such as oleic acid, stearic acid, palmitic acid,rlcinoleic acid, etc. Acids derived from rosins such as .abietic acidrepresents another class.

Similarly, carboxy acids derived from petroleum,

the formation of a detergent as abietic acid itself, and such functionalderivatives are considered as detergent-forming acids. Reference is madeto U. S. Patent #1,988,835, to De Groote and Wirtel, dated January 22,1935. 5 This particular patent describes a process for breakingpetroleum emulsions of the water-in-oil type, which consists insubjecting the emulsion to the action of a demulsifying agent containinga sulfo-aliphatic ester of a fatty acid of the type 10 R".C00(T.SO3.Z),in which R" is a fatty acid radical, C00 is a carboxyl residue, T is thealiphatic residue, 5031s the conventional sulfonic acid residue, Zrepresents the acidic hy-' drogen atom of thesulfonic acid or itsequiva- 15 lentwand (T.SOa.Z) replaces the carboxylic hydrogen.

. Reference is also made to U. S. Patent #2,077,- 745, to De Groote,dated April 20, 1937. This particular patent describes a process forbreaking 20 petroleum emulsions of the water-in-oil type, which consistsin subjecting the emulsion to the action of a demulsifying agent of thekind ink dicated by the type formula:

R.COO.T(OH)1i(SO4.Z )m

in which RG00 is the carboxy acid radical derived from adetergent-forming carboxy acid; T(OH) is the residue from a polyhydricalcohol; S04 is the sulfate radical; and Z is the 30 ionizable hydrogenequivalent; 1!. represents the numeral 0, 1 or more; and m representsthe numeral 1 or more.

Reference is also made to U. S. Patent #2,052,- 284, to De Groote, datedAugust 25, 1936, which 7 35 describes a process for breaking petroleumemulsions by the action of a demulsifying agent comprising a chemicalcompound of the formula type: (R1100) m.T.(OH) m, in which R.COOrepresents a non-sulfo, detergent-forming, monocarboxy acid radical, Trepresents a polyhydric alcohol residue, and m indicates the numeral 1or more, and R and T being additionally characterized by freedom from anextraneous acid residue.

I have found that certain oil field emulsions which, althoughsusceptible to -1 or more of .the types of demulsifying agent previouslydescribed, are even more susceptible to a reagent characmrized by beingof the following type formula:

in which R.COO is a carboxy acid radical derived from adetergent-forming carboxy acid,

T(0H)1l is a residue derived from a polyhydric alcohol of the kind whichin unaltered form contains at least three hydroxyls, n being the numeral1, 2, or 3, and SO3Z being the typical sulfonic acid radical, in which Zrepresents 'an ionizable hydrogen atom equivalent.

Compounds of the kind contemplated for use as demulsifying agents in thepresent process may be prepared in any suitable manner. Various methodsare known for the preparation of soluble salts of 1:2 dihydroxy propane:3 sulfonic acid. Such material can be esterified with a mole of anysuitable detergent-forming carboxy acid, and particularly various fattyacids or modified fatty acids of the kind previously described. Anothersuitable procedure is to treat the soluble salts of l halogen :2 hydroxypropane :3 sulfonic acid with suitable fatty acid salts or the like, soas to eliminate an inorganic halide, such as sodium chloride.

Examples of well known procedures for producing reagents of the kindherein contemplated as demulsifying agents include the following:

Example 1 180 parts of the sodium salt of glycerol sulfonic acid (sodium1:2-dihydroxy propane 3-sulfonate, prepared by heatingalpha-chlorohyclrin derived from glycerol with aqueous NazSOa solutionand subsequent removal of water) are heated at 150 to 225 C. for 6 hourswith stirring with 210 parts of the fatty acids from cocoanut oil, thewater evolved in the reaction being allowed to escape and the fattyacids being returned to the reacting chamber by suitable refluxcondensation. The product of this reaction is then purified by washingwith cold ethyl alcohol or other low-boiling alcohol, or preferably bydissolving in hot ethyl alcohol, filtering to remove insoluble inorganicsalts, or other insoluble matter and crystallizing from the acoholicsolution.

Example 2 200 parts of the sodium salt of 1-chloro 2-hydroxy propane:3-sulfonic acid (prepared by first treating one mole of glycerine withtwo moles of chlorine to form CH2ClCHOH-CH2C1, and then reacting onemole of this product with one mole of sodium sulfite to form are heatedat to 200 C. with stirring for 5 hours with 300 parts of sodium soapprepared from tallow. The product of the reaction may then be purifiedas in Example 1.

Example 3 A triethanolammonium (sometimes called triethanolamine)compound may be formed as follows:

290 parts of the sodium salt of commercial stearic acid are heated atabout C., with stirring for 4 hours with 325 parts of thetriethanolammonium salt of l-chloro 2-hydroxy propane 3-su1fonic acid(prepared by heating 1:3 dichlorohydrin with triethanolammoniumsulfite). The product of the reaction may be purified as in Example 1.

In some instances it is more economical to employ the dichlorhydrin asthe raw material rather than the monochlorhydrin. The reason is that thedichlorhydrin can be prepared very economically by means of sulfurmonochloride. See Systematic Organic Chemistry, Cumming, Hopper,Wheeler, 1931, p. 335.

It is obvious that other polyhydroxylated materials may replace glycerolprovided that they containat least three alcoholic hydroxyls. Forinstance, one could prepare the monbchlorhydrin or the dichlorhydrinfrom diglyc'erol, which is an ether alcohol, and employ such materialjust as advantageously as a corresponding compound derived fromglycerol. Similarly, one couldt prepare an ether alcohol from diglyceroland -a monohydric alcohoL-such as ethyl alcohol, and employ such etheralcohol in place of glycerol, provided that the compound contained atleast three alcoholic hydroxyls and provided that it could be convertedreadily so as to yield amonochlorhydrin and a dichlorhydrin. Similarly,ether alcohols could be obtained by reaction between a glycol, such asethylene glycol, propylene glycol, or the like, and glycerol. The etheralcohols so obtained could be converted into a monochlorhydrin or adichlorhydrin and these materials employed in the manner previouslydescribed.

It is understood that reference to a polyhydric alcohol or a polyhydricalcohol residue refers to the ether type as well as the non-ether type.Whenever it is intended to limit the meaning to polyhydric alcohols orpolyhydric alcohol residues, as differentiated from the polyhydricalcohol ethers or polyhydric alcohol ether residues, the expression freefrom an ether linkage will be employed.

Although it has been pointed out that the detergent-forming carboxy acidmay be supplied by a resin acid, such as abietic acid, chlorabieticacid, sulfoabetic acid, or the like, or may be furnished by a petroleumcarboxy acid, such as naphthenic acid, sulfonaphthenic acid, or the Theexpression modified fatty acids" is wellunderstood by those skilled inthe art of resolving petroleum emulsions of the water-in-oil type, andhas been used frequently in the patent literature to designate a certainWell known class of materials. Briefly described, modified fatty acidsare modifications of fatty acids obtained by chemical reaction on afatty acid or its equivalent, so as to result in an addition product orsubstitution product, and they bear a simple genetic relationship toeach other or to the parent fatty acid or fatty acid compound from whichthey were derived. Modified fatty acids do not include salts ofunmodified fatty acids, such as soaps, because a salt of a fatty acid isnot an addition product. Likewise, it is not a substitution product,because substitution products" in the sense that such term is used. inorganic chemistry, is applied not to salts, but to undissociable orindiiferent compounds. Furthermore, whereas the acid hydrogen involvedin salt formation can be replaced only by metals or metal-like groups,that is, elements or radicals which are electropositive, substitutionmay replace the hydrogen of organic compounds by a variety of elementsand groups which may be electro-negative.

The treating agent or demulsifying agent contemplated by my processincludes esters of the specific kind described, and may be derived fromemployed as the demulsifying agent of my process.

I desire to point out that the superiority of the reagent ordemulsifying agent contemplated in my process is based upon its abilityto treat certain emulsions more advantageously and at a somewhat lowercost than is possible with other available demulsifiers, or conventionalmixtures thereof. It is believed that the particular demulsifying agentor treating agent herein described will find comparatively limitedapplication, so far as the majority of oil field emulsions areconcerned; but I have found that such a demulsifying agent hascommercial value, as it will economically break or resolve oil fieldemulsions in a number of cases which cannot be treated as easily or atso low a cost with the demulsifying agents heretofore available.

In practising my process, a treating agent or demulsifying agent of thekind described above may be brought in contact with the emulsion to betreated in any of the numerous ways now employed in the treatment ofpetroleum emulsions of the water-ln-oil type with chemical demulsifyingagents, such, for example, as by introducing the treating agent into thewell in which the emulsion is produced; introducing the treating agentinto a conduit through which the emulsion is flowing; introducing thetreating agent into a tank in which the emulsion is stored; orintroducing the treating agent into a container that holds a sludgeobtained from the bottom of an oil storage tank. In some instances, itmay be advisable to introduce the treating agent into at producing wellin such a way that it will become mixed with water and oil that areemerging from the surrounding strata, before said water and oil enterthe barrel of the well pump or the tubing up through which said waterand oil flow to the surface of the ground. After treatment, the emulsionis allowed to stand in a quiescent state, usually in a settling tank,and usually at a temperature varying from atmospheric temperature toabout 200 0., so as to permit the water or brine to separate from theoil, it being preferable to keep the temperature low enough to preventthe volatilization of valuable constituents of the oil. If desired, thetreated emulsion may be acted upon by one or more of the various kindsof apparatus now used in the operation of breaking petroleum. emulsions,such as homogenizers, hay tanks, gun barrels, filters, centrifuges, orelectrical dehydrators.

The amount of treating agent that may be required to break, the emulsionmay vary from approximately one part of treating agent to 500 parts ofemulsion, up to one part of treating agent to 20,000, or even 30,000parts of emulsion. The proportion depends on the type of emulsion beingtreated, and also upon the equipment being used, and the temperatureemployed. In treating exceptionally refractory emulsions of the kindsknown as tank bottoms and residual pit oils, the ratio of 1:500, abovereferred to, may be required. In treating fresh emulsion, l. e.,emulsions that will yield readily to the action of chemical demulsifyingagents, the ratio of 1:30,000, above referred to, may be sufllcient toproduce highly satisfactory results. In general, I have found that foran average petroleum emulsion a ratio of one part of treating agent to5,000 parts or 10,000 parts of emulsion will usually be found to producecommercially satisfactory results.

aioacas Having thus described my invention, what I claim new and desireto secure by Letters Pat out is:

1. A process for breaking petroleum emulsions of the water-in-oil type,which consists in subjecting the emulsion to the action of ademulsifying agent comprising a compound of the formula type:

in which H.000 is a carboxy acid radical derived from adetergent-forming carboxy acid; T(OH)7= is a residue derived from apolyhydric alcohol of the kind which in unaltered form contains at leastthree hydroxyl groups; n is the numeral 1, 2 or 3; and S032; is thetypical sulfonic acid radical in which Z represents an ionizablehydrogen atom equivalent.

2. A process for breaking petroleum emulsions of the water-in-oil type,which consists in subjecting the emulsion to the action of ademuisifying agent comprising a compound of the formula in w.ich RG00 acarboxy acid radical derived ircm a rosin acid; ITOHM is a residuetierived from a polyhydric alcohol of the kind which in unaltered formcontains at least three hydroxyl groups; n is the numeral 1, 2 or 3; andS032 is the typical sulfonic acid radical in which Z represents anionizable hydrogen atom equivalent.

3. A process for breaking petroleum emulsions of the water-in-oil type,which consists in subjecting the emulsion to the action of ademulsilying agent comprising a compound oi. the formula type:

RCOQIJKOH) 1&(3032) in which H.600 is a carboxy acid radical derivedfrom a petroleum acid; T OH n is a residue derived from a polyhydricalcohol of the kind which in unaltered form contains at least threehydroxyl groups; n is the numeral 1, 2 or 3; and S032 is the typical.sulfonic acid radical in which Z represents an ionizable hydrogen atomequivalent.

4. A process for breaking petroleum emulsions of the water-in-oil type,which consists in subjecting temulsion to the action of a demulsifyingagent ccunprising a compound of the formula type:

HJFJOO.T(OH) 12(8032) in which 13.000 is a carboxy acid radical derivedfrom a higherfatty acid; T(OH)n is a residue, free from an etherlinkage, and derived from a polyhydric alcohol of the kind which inunaltered form contains at least three hydroxyl groups: n is the numeral1, 2 or 3; and S032 is the typical in which R.COO is a carboxyacidradical derived from a higher fatty acid; T(-H)n is the bivalent radicalCaHOH; and SOaZ is the typical sulfonic acid radical in which Zrepresents an ionizable hydrogen atom equivalent.

7. A process for breaking petroleum emulsions oi the water-in-oil type,which consists in subjecting the emulsion to the action of ademulsifying agent comprising a compound of the formula type:

R.COO.T(OH)1.(SO3Z) in which R.COO is a carboxy acid radical de-' Jrived from a hydroxylated higher fatty acid;

ing agent comprising a compound of the formula type:

R.CO0.T (OH) MSOaZ) in which R.COO is a carboxy acid radical derivedfrom a hydroxylated higher fatty acid; T(O.H)n is the bivalent radicalCaHsOH; and SOaZ is the typical sulfonic acid radical in which Zrepresents a metallic atom.

9. A process for breaking petroleum emulsions of the water-in-oil type,which consists in subjecting the emulsion to the action of ademulsiiying agent of the water-soluble type comprising a compound ofthe formula type:

in which R.COO is a carboxy acid radical derived from a hydroxylatedhigher fatty acid; T(OH)11 is the bivalent radical CsHsOH; and S032 isthe typical sulfonic acid radical in which Z represents a metallic atom.

10. A process for breaking petroleum emulsions of the water-in-oil type,which consists in subjecting the emulsion to the action of ademulsifying agent comprising a compound of the formula type:

OH.C3H5.CmHrizOI-IQOOSOaNa MELVIN DE GROO'I'E.

